Air conditioning system

Abstract

An air-conditioning system for a cooling operation and a heating operation comprises a first heat exchanger to which a high-pressure and high-temperature refrigerant which has not been substantially cooled and adiabatically expanded after being compressed is supplied to heat the inside of a room to be air-conditioned during both of the cooling operation and the heating operation, a second heat exchanger to which a low-pressure and low-temperature refrigerant which has been substantially cooled and adiabatically expanded after being compressed is supplied to cool the inside of the room during both of the cooling operation and heating operation, and an air flow generator for generating an air flow which passes the first heat exchanger and the second heat exchanger, wherein the second heat exchanger is arranged at an upstream side of the first heat exchanger in the air flow.

What is claimed is: 
     
       1. An air-conditioning system for a cooling operation and a heating operation comprising, a first heat exchanger to which a high-pressure and high-temperature refrigerant which has not been substantially cooled and adiabatically expanded after being compressed is supplied to heat an inside of a room to be air-conditioned,   a second heat exchanger to which a low-pressure and low-temperature refrigerant which has been substantially cooled and adiabatically expanded after being compressed is supplied to cool the inside of the room,   an air flow generator for generating an air flow which passes the first heat exchanger and the second heat exchanger,   a first temperature sensor for measuring a temperature of the inside of the room,   a second temperature sensor for measuring a temperature of the air flow which has passed the first and second heat exchangers, and   a temperature adjusting means for determining a desired temperature of the air flow which has passed the first and second heat exchangers on the basis of a difference between a predetermined temperature and the temperature of the inside of the room measured by the first temperature sensor, and for controlling a ratio of a flow rate of the refrigerant flowing through the first heat exchanger to a flow rate of the refrigerant flowing through the second heat exchanger to change the temperature measured by the second temperature sensor to the desired temperature.   
     
     
       2. An air-conditioning system according to claim 1, wherein the temperature measured by the second temperature sensor ius made higher than the predetermined temperature when the temperature measured by the first temperature sensor is lower than the predetermined temperature. 
     
     
       3. An air-conditioning system according to claim 1, wherein the temperature measured by the second temperature sensor is made substantially equal to the predetermined temperature when the temperature measured by the first temperature sensor is substantially equal to the predetermined temperature. 
     
     
       4. An air-conditioning system according to claim 1, wherein the temperature measured by the second temperature sensor is made lower than the predetermined temperature when the temperature measured by the first temperature sensor is higher than the predetermined temperature. 
     
     
       5. An air-conditioning system according to claim 1, wherein the predetermined temperature is a desired temperature of the inside of the room. 
     
     
       6. An air-conditioning system according to claim 1, wherein the air flow generated by the air flow generator passes the first heat exchanger after passing the second heat exchanger. 
     
     
       7. An air-conditioning system according to claim 1, wherein the second heat exchanger is arranged at an upstream side of the first heat exchanger in the air flow. 
     
     
       8. An air-conditioning system according to claim 1, wherein the system further comprises a third heat exchanger for cooling the refrigerant after being compressed and an adiabatic expansion orifice at which the refrigerant after being compressed and cooled expands adiabatically and from which the low-pressure and low-temperature refrigerant which has been substantially cooled and adiabatically expanded after being compressed is supplied to the second heat exchanger, the temperature adjusting means controls the flow rate of the refrigerant flowing through the first heat exchanger, and the refrigerant flowing from the first heat exchanger and from the third heat exchanger flows into the second heat exchanger through the adiabatic expansion orifice. 
     
     
       9. An air-conditioning system according to claim 1, wherein the system further comprises a third heat exchanger for cooling the refrigerant after being compressed and an adiabatic expansion orifice at which the refrigerant after being compressed and cooled expands adiabatically and from which the low-pressure and low-temperature refrigerant which has been substantially cooled and adiabatically expanded after being compressed is supplied to the second heat exchanger, the refrigerant flowing from both of the first heat exchanger and the third heat exchanger flows into the second heat exchanger through the adiabatic expansion orifice, and the temperature adjusting means controls the flow rate of the refrigerant flowing through the second heat exchanger. 
     
     
       10. An air-conditioning system according to claim 1, wherein the system further comprises a third heat exchanger for cooling the refrigerant after being compressed and an adiabatic expansion orifice at which the refrigerant after being compressed and cooled expands adiabatically and from which the low-pressure and low-temperature refrigerant which has been substantially cooled and adiabatically expanded after being compressed is supplied to the second heat exchanger, the temperature adjusting means controls the flow rate of the refrigerant flowing from the third heat exchanger to the second heat exchanger, and the refrigerant flowing from the first heat exchanger and from the third heat exchanger flows into the second heat exchanger through the adiabatic expansion orifice. 
     
     
       11. An air-conditioning system according to claim 1, wherein the refrigerant cooled in the first heat exchanger is supplied to the second heat exchanger after an adiabatic expansion thereof. 
     
     
       12. An air-conditioning system according to claim 11, wherein the refrigerant cooled in the first heat exchanger is further cooled by the refrigerant flowing out from the second heat exchanger, before the adiabatic expansion thereof. 
     
     
       13. An air-conditioning system according to claim 1, wherein the first temperature sensor is arranged at an upstream side of the second heat exchanger in the air flow. 
     
     
       14. An air-conditioning system according to claim 1, wherein the temperature adjusting means is controlled to increase the flow rate of the refrigerant flowing through the first heat exchanger in relation to the flow rate of the refrigerant flowing through the second heat exchanger when the temperature measured by the first temperature sensor is lower than the predetermined temperature, and the temperature adjusting means is controlled to decrease the flow rate of the refrigerant flowing through the first heat exchanger in relation to the flow rate of the refrigerant flowing through the second heat exchanger when the temperature measured by the first temperature sensor is higher than the predetermined temperature. 
     
     
       15. An air-conditioning system according to claim 1, wherein the temperature adjusting means is controlled to decrease the flow rate of the refrigerant flowing through the second heat exchanger in relation to the flow rate of the refrigerant flowing through the first heat exchanger when the temperature measured by the first temperature sensor is lower than the predetermined temperature, and the temperature adjusting means is controlled to increase the flow rate of the refrigerant flowing through the second heat exchanger in relation to the flow rate of the refrigerant flowing through the first heat exchanger when the temperature measured by the first temperature sensor is higher than the predetermined temperature. 
     
     
       16. An air-conditioning system according to claim 1, wherein the system further comprises a humidity sensor for measuring a humidity in the inside of the room, the temperature adjusting means is controlled in accordance with a difference between the humidity measured by the humidity sensor and a predetermined humidity so that the difference is decreased. 
     
     
       17. An air-conditioning system according to claim 16, wherein the temperature adjusting means is controlled to decrease the flow rate of the refrigerant flowing through the second heat exchanger when the humidity measured by the humidity sensor is lower than the predetermined humidity, and the temperature adjusting means is controlled to increase the flow rate of the refrigerant flowing through the second heat exchanger when the humidity measured by the humidity sensor is higher than the predetermined humidity. 
     
     
       18. An air-conditioning system according to claim 1, wherein the second temperature sensor is arranged at a downstream side of the first heat exchanger in the air flow. 
     
     
       19. An air-conditioning system according to claim 1, wherein the temperature adjusting means is controlled to increase the flow rate of the refrigerant flowing through the first heat exchanger in relation to the flow rate of the refrigerant flowing through the second heat exchanger when the temperature measured by the second temperature sensor is lower than the predetermined temperature, and the temperature adjusting means is controlled to decrease the flow rate of the refrigerant flowing through the first heat exchanger in relation to the flow rate of the refrigerant flowing through the second heat exchanger when the temperature measured by the second temperature sensor is higher than the predetermined temperature. 
     
     
       20. An air-conditioning system according to claim 1, wherein the temperature adjusting means is controlled to decrease the flow rate of the refrigerant flowing through the second heat exchanger in relation to the flow rate of the refrigerant flowing through the first heat exchanger when the temperature measured by the second temperature sensor is lower than the predetermined temperature, and the temperature adjusting means is controlled to increase the flow rate of the refrigerant flowing through the second heat exchanger in relation to the flow rate of the refrigerant flowing through the first heat exchanger when the temperature measured by the second temperature sensor is higher than the predetermined temperature. 
     
     
       21. An air-conditioning system according to claim 1, wherein the system further comprises a third temperature sensor for measuring a temperature of the air flow between the first heat exchanger and the second heat exchanger, the temperature adjusting means is controlled in accordance with a difference between the temperature measured by the third temperature sensor and a predetermined temperature so that the difference is decreased. 
     
     
       22. An air-conditioning system according to claim 21, wherein the system further comprises a fourth temperature sensor for measuring a temperature of the refrigerant which has not been substantially heated in the second heat exchanger and a fifth temperature sensor for measuring a temperature of the refrigerant which has been substantially heated in the second heat exchanger, the temperature adjusting means is controlled to decrease the flow rate of the refrigerant flowing through the second heat exchanger when a difference between the temperature measured by the fourth temperature sensor and the temperature measured by the fifth temperature sensor is smaller than a predetermined degree. 
     
     
       23. An air-conditioning system according to claim 1, wherein the second heat exchanger and the first heat exchanger are integrally connected to each other.